register Disconnect handler soon enough

src/common/connection.py

@@ -615,11 +615,11 @@ def _connect_success(self, con, con_type):
 		if _con_type != self._current_type:
 			self.connect_to_next_type()
 			return
+		con.RegisterDisconnectHandler(self._on_disconnected)
 		if _con_type == 'plain' and gajim.config.get_per('accounts', self.name,
 		'warn_when_plaintext_connection'):
 			self.dispatch('PLAIN_CONNECTION', (con,))
 			return True
-		con.RegisterDisconnectHandler(self._on_disconnected)
 		if _con_type in ('tls', 'ssl') and not hasattr(con.Connection,
 		'_sslContext') and gajim.config.get_per('accounts', self.name,
 		'warn_when_insecure_ssl_connection') and \